This way, there’s not need to mess with iptables-persistant and if you installed iptables-persistent you’ll need to uninstall it running sudo “apt-get purge iptables-persistent”.

Use “Sudo xed” in a terminal to get an editor so you can edit the file mentioned above. Copy / Paste the settings above at the end of the after.rules file and save it. You can safely ignore the errors about meta data that xed spits out. It’s trying to save some meta data about the formatting and of course that is nonsense when you are editing system files.